Binocular vision contributes to the visual ability of figure-ground segmentation and fine depth discrimination. Retinal images of 3-D visual scenes from the two eyes usually have the same mean contrast energy over time. This suggests that the binocular visual system is built to treat the inputs from the two eyes equally in order to achieve a high proficiency. Indeed, for a standard observer, stimuli with equal contrast in each eye induces superior binocular perception, as compared to stimuli with unequal contrast levels.
The interocular integration and inhibitory mechanisms that are part of the binocular neural network support a variety of binocular visual functions including summation, fusion, stereopsis and suppression. Both mechanisms work together, with the interocular inhibitory mechanism suppressing dissimilar images from one or both eyes, to achieve a coherent 3-D representation of the visual scene. Binocular visual processing is adversely affected, however, when an observer's eyes are not equally strong, i.e. one eye is dominant over the other and provides a larger weighted contribution to the binocular neural network. Indeed, human observers with a significant degree of unbalanced interocular inhibition, often called sensory eye dominance (SED), tend to have degraded binocular visual processing and reduced binocular depth perception.
The magnitude of SED varies in the population along a continuum. At one end, observers with minor SED have clinically normal stereoacuity. At the other end, however, observers with strong SED have little or no stereopsis. Examples of the latter include amblyopia and strabismus, which are also characterizable by a host of visual deficits related to contour integration, spatial and temporal vision, as well as those related to higher level visual functions.
There is a continuing need for establishing treatment methods and regimens that can correct SED, amblyopia, strabismus, and/or otherwise improve a patient's stereopsis and/or binocular imbalance. In particular, there is a need for a system, method, or protocol, that can reduce and/or correct binocular imbalance in a subject, improve the visual impairments associated with the dominance of one eye of a subject over the other, and/or otherwise improve a subject's ability to resolve the three-dimensional structure and/or depth perception relative to a given object. The present invention addresses at least these needs.